<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0，user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    #box{
        width: 100px;
        height: 100px;
        background: red;
    }
    </style>
    <script>
        alert(window.devicePixelRatio);
    </script>
</head>
<body>
    我的第一个移动端页面
    <div id="box"></div>
</body>
</html>